Walmart is signing a long-term contract to buy nuclear power for the first time ever, a promising sign that the industry’s future is supported by more than just the AI data center boom.

The retail giant agreed on Tuesday to buy power from a nuclear plant in Illinois owned by Constellation Energy for its operations in the area, including its stores and a high-tech warehouse in Illinois that stores and sorts perishable food.

Walmart will buy 176 megawatts of power from the plant over a 15-year period, or enough power to serve around 150,000 homes.

The financial terms were not disclosed, but these types of deals tend to go for premium prices because they allow the buyer to lock in their costs over a long period.

Walmart, which has pledged to eliminate net carbon emissions from its U.S. operations by 2040, will also receive the environmental attributes associated with the nuclear energy, which generates electricity without carbon emissions.

Constellation stock was down 0.3% on Tuesday, outperforming the S&P 500’s decline.

The deal isn’t large enough to significantly boost Constellation’s growth trajectory, given that Constellation has 55 gigawatts worth of generating capacity and the Walmart deal represents less than 0.5% of that total.

Still, investors are eager to see Constellation sign more long-term power agreements, particularly with technology companies seeking electricity for AI data centers.

A lack of similar announcements has contributed to the stock’s 25% decline this year, following multiple years of double-digit gains.

Write to Avi Salzman at avi.salzman@barrons.com